1. Field of the Invention
The present invention relates to systems and methods for surgical access, and more particularly, to systems and methods for supplying pressurized fluid to surgical devices.
2. Description of Related Art
Laparoscopic, or “minimally invasive” surgical techniques are becoming increasingly more common. Benefits of such procedures include reduced trauma to the patient, reduced opportunity for infection, and decreased recovery time. Such procedures within the abdominal cavity are typically performed through a device known as a trocar or cannula, which facilitates the introduction of laparoscopic instruments into the abdominal cavity of a patient.
Additionally, such procedures commonly involve filling or “insufflating” the abdominal (peritoneal) cavity with a pressurized fluid, such as carbon dioxide, to create what is referred to as a pneumoperitoneum. The insufflation can be carried out by a trocar equipped to deliver insufflation fluid, or by a separate insufflation device, such as an insufflation needle. Introduction of surgical instruments into the pneumoperitoneum without a substantial loss of insufflation gas is desirable in order to maintain the pneumoperitoneum.
During typical laparoscopic procedures, a surgeon makes three to four small incisions which are usually no larger than about twelve millimeters each, and typically made with the trocar devices themselves by using a separate inserter or obturator placed therein. Following insertion, the inserter is removed, and the trocar allows instruments to be inserted therethrough into the abdominal cavity. Typical trocars often provide means to insufflate the abdominal cavity so that the surgeon has an open interior space in which to work.
Once inserted, the trocar must provide a means to maintain the pressure within the cavity, which requires providing a seal between the trocar and the surgical instruments being used while allowing at least some freedom of movement of the surgical instruments. Such instruments can include, for example, scissors, grasping instruments, occluding instruments, cauterizing units, cameras, light sources, and other surgical instruments. Sealing elements and mechanisms are typically provided on the trocars to prevent the escape of insufflation gas. Sealing elements and mechanisms typically include a duckbill-type valve made of a relatively pliable material, and are configured to seal around an outer surface of surgical instruments passing through the trocar. However, sealing performed in this manner cannot seal between multiple instruments, and inhibits free movement of the surgical instruments and/or removal of tissue through the trocar. Such seals are also vulnerable to damage during the surgical procedure. Alternatively, a flapper valve or spring-loaded trap door can be used. However, these types of mechanical valves suffer from similar drawbacks.
Most valves, and particularly duckbill-type valves which include resilient valve members that directly contact surgical instruments, not only interfere with the movement of surgical instruments, but also reduce the ability of a surgeon to accurately sense the anatomy of the patient on which the surgeon is operating. While minimally invasive surgical procedures are carried out with a visualization aid such as a camera, the surgeon's depth perception is inhibited during the procedure. Moreover, when the endoscope passes through mechanical seals, the camera lenses thereof can be dirtied, typically with smears appearing, which results in further vision difficulty. In the absence of such mechanical seals, specimens can be extracted without excessive interference. Additionally, the ability of the surgeon to physically sense resistance of structures and tissues through movement of the surgical instruments plays an important role in the success and safety of the surgical procedure. Frictional forces imparted on surgical instruments by contact of the aforementioned mechanical valves can mask the sensory signals, i.e., the haptic perception, that the surgeon might otherwise use to determine precisely what is occurring at the opposite end of the surgical instruments being used.
One type of seal utilized more recently during surgical procedures is a fluidic or pneumatic seal provided in a trocar assembly coupled to a source of pressurized fluid. The trocar assembly is inserted into a cavity (e.g., the abdominal cavity) of a patient, and defines a lumen which provides access to the cavity. The pressurized fluid is directed to the lumen of the trocar assembly to provide a pneumatic seal within the lumen. In this manner, surgical instruments may be passed through the lumen and pneumatic seal and maneuvered within the body cavity. The pressurized fluid flows around the surgical instruments inserted therethrough, maintaining the pneumatic seal in the trocar assembly and a pressure differential between the body cavity of the patient and the outside environment while causing minimal friction forces on the surgical instruments as they are maneuvered through the trocar assembly at the operation site.
While conventional methods and systems for sealing technologies have generally been considered satisfactory for their intended purpose, there is still a need in the art for improved systems and methods which are easy to make and use for providing unencumbered access to a body cavity, and for operation of surgical access devices while maintaining the pneumoperitoneum created during insufflation.